net.ipv6.conf.all.send_redirects

[George Bonser]

> -----Original Message-----
> From: ipv6-ops-bounces+gbonser=seven.com at lists.cluenet.de [mailto:ipv6-
> ops-bounces+gbonser=seven.com at lists.cluenet.de] On Behalf Of Bit Gossip
> Sent: Sunday, January 03, 2010 1:18 PM
> To: ipv6-ops at lists.cluenet.de
> Subject: net.ipv6.conf.all.send_redirects
> 
> Experts,
> in IPv4 it was possible to disable sending ICMP redirect as simple as:
> 
> # sysctl -w net.ipv4.conf.all.send_redirects=0
> net.ipv4.conf.all.send_redirects = 0
> 
> Unfortunately the same key seems to have disappeared in IPv6:
> 
> # sysctl -w net.ipv6.conf.all.send_redirects=0
> error: "net.ipv6.conf.all.send_redirects" is an unknown key
> 
> Any idea how to disable sending ICMP redirect?
> Thanks!


It is my understanding that redirects are sent only if the unit is a router and the protocol spec says that if a unit is a router than it MUST support the sending of redirects ( RFC4294 §4.2 )

So if you turn off redirects on an IPv6 router, you have broken IPv6.  In other words, in IPv6, redirects are not optional in sending according to the RFC.